That the speaker has the time between "now" (when the speaker said it) until the woman makes food, to do something.
The same reason you wouldn't need it in English, though in both languages this is probably more likely to be an answer to a question
In German and English you don't need to say the word time here either. At least for German I can say it's very common to say ich habe noch (Zeit), bis die Frau kocht. Literally: I have still (time) until the woman cooks. noch (still) is there to indicate that's the time left.
I always translate 'mad' into 'meal' but it's not accepted. I'm not a native English speaker, but is it wrong if I say 'the woman makes meal' ?
If you want to use that sentence it would be "the woman makes the meal" or even better, "the woman is making the meal".
The other thing is that the phrase "laver mad" means "cooking" or "cooks". It's the same as the Swedish "lagar mat". You don't have to use the word "food" at all.
The sentence needs a context to make sense. Without that, it really needs an object for 'have' -- in English and I would assume in Danish.